Application of Tire Derived Aggregates in Seismic Response of Railway Embankments

Railways are an important part of infrastructure that work to deliver materials and people quickly across far distances with fewer emissions than transportation through vehicles in traffic. Damage to railways from seismic events can lead to train derailments due to deformation of the railway embankment. Previous experimental studies have shown that addition of tire derived aggregates (TDA) in the sub-ballast layer of railway embankments decreases the displacement of the embankment due to seismic loading. In this study, a finite element model is created to determine the optimum amount of TDA that can be added to the sub-ballast layer in order to improve the seismic behavior of railway embankments. Four models, conventional (100% sand), sand with 15% TDA, sand with 20% TDA, and sand with 25% TDA, are considered. The models are subjected to an earthquake loading, and the displacement and acceleration results of three points on the embankments are recorded. The obtained results indicated that addition of TDA in the sub-ballast layer reduces the maximum acceleration and maximum displacement of the railway embankment under seismic loading. As the optimum percentage of TDA, values around 20%-25% can be proposed for practical uses.